Missing grandgrandfather from Serbia in Uruguay

I’m trying to find any information about my great grandfather (or his descendants) that left Serbia in April 1928 and never came home again. His name was Vlajko Pani? (?????? ????? in Serbian alphabet), born in Balta Berilovac, Serbia, 1907. He arrived to Montevideo, Urugvay in 1928 and wrote regularly to his family until the Second World War. His family only heard from him once after that (last letter arrived in 1956) and after that my grandfather’s reply letter returned unopened from Uruguay. After that we don’t have any information what happened to him. We don’t know how and when he died, or where he died, or anything about his new family in Uruguay. There were some rumors from people that returned from Uruguay that he started new family there. His last known address was Gergiollos Depart, De Geniolles, Republic Uruguay (errors in spelling are possible, it was written down by my great grandmother). Can anyone help us locate any sources where might be any information about him, or how to trace his family. Our family in Serbia is hoping to get any information to eventually locate his descendants and get to contact with them.